These CCTV images show a man they want to identify after a series of attacks on women in the city this week.
The four incidents happened in the Harehills and Burmantofts areas on Monday and Tuesday.
Police believe the same suspect is responsible and said they were concerned that he could strike again.
Detective Inspector Phil Jackson, of Leeds District CID, said: “We are investigating these incidents as a linked series and believe the same suspect was responsible. Clearly they were distressing experiences for the victims and we are very concerned to have had so many in such a short space of time.
“We are concerned that this man will commit further offences and we urgently need to identify him and arrest him.”
A 48-year-old woman was sexually assaulted in Nippet Lane, Burmantofts, by the suspect as he cycled past on a BMX bike at about 11.50am on Monday.
He rode off towards Torre Road.
Three further incidents happened on Tuesday between 6am and 6.20am.
The suspect sexually assaulted a 19-year-old woman in Nowell Walk, a 36-year-old woman in Nowell Parade at the junction with Nowell Street, and another woman in Harehills Lane.
The man was described as a dark-skinned black male, possibly East African, with curly hair that was couple of inches long in a pony tail.
He was wearing a grey hooded top with dark-coloured patches, grey trousers and black trainers with pink on them.
Det Insp Jackson said: “We have recovered CCTV images of him and, although his face is not clear, we feel he will be recognisable to anyone who knows him from the local area.
“We would ask anyone who knows who he is or who has any information that could assist the investigation.”
Anyone with information is asked to contact Detective Constable 5964 David White or Detective Constable 6696 Abid Saleem at Leeds District CID quoting crime number 13160382727 or call the independent charity Crimestoppers anonymously on 0800 555 111.